+1 On oil coming from breather.
The oil seals on the exhaust turbine side of mine failed at around 19k, allowing oil to leak directly into the exhaust.
Got a refurbished turbo installed, so was sure of no oil leaks anywhere but still had oil ingress into the intercooler until I routed the breather into a catch can. With the engine running warm, there isn't excessive pressure coming out of the breather like on very worn engines, but there was a lot of mist coming out of it. I am guessing this oil mist is what condenses back into liquid in the intercooler.
It's just possible your engine may be just a little bit tired.